I do not know how to use this application help

I think you're doing well so far

Start by reading through the articles on the MFP Help pages; those will answer many of your initial questions.
https://myfitnesspal.desk.com/customer/portal/topics/455841-general-questions-getting-started/articles

Grantali2 wrote: »

Hey anyone know why the app doesn't seems to count calories from weight lifting?

Add "Strength training (weight lifting, weight training)" to Cardiovascular to get estimated Calories Burned added to your Diary. Please note that the Calories burned for Cardiovascular exercises provided by MFP are based on published metabolic equivalent of tasks (METs), which are estimates for a general population and may differ for you as an individual. If desired, add individual strength training exercises, such as "Biceps Curl," to Strength Training to have a log of sets, reps, and weights as individual exercises.

Please see these articles in the list of articles on this topic in the MFP Help pages...
myfitnesspal.desk.com/customer/portal/articles/11170-why-don-t-you-calculate-calories-burned-for-strength-training-
myfitnesspal.desk.com/customer/portal/topics/455842-exercise-diary-and-exercise-database/articles